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    <title>Document</title>
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<script>
    let s1 = Symbol(1)
    let s2 = Symbol(1)
    if(s1==s2){
        console.log("一样");
    }else{
        console.log("两个不一样");
    }//symbol定义的值是独一无二的，+输出else里面的log
</script>
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